Skin Packaging Machine

ABSTRACT

A skin packaging machine in which a first continuous film and a second continuous and thermoplastic film above the first film are supplied in a forward direction of the machine. The machine includes a sealing station configured for receiving both films, and it comprises an upper tool pressing on the films to seal them to one another, with a closed holding contour delimiting the area of said films being sealed. The sealing station further comprises a sealing gasket attached to the holding contour, the sealing gasket having, on each side with respect to the forward direction, an operation zone with a notched configuration which is facing the space delimited by said sealing gasket.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application relates to and claims the benefit and priority toEuropean Application No. EP16382497.2, filed Oct. 28, 2016.

TECHNICAL FIELD

The present invention relates to skin packaging machines, by means ofusing a first film and a second film between which products arepackaged.

BACKGROUND

The use of skin packaging machines supplying a first film on whichproducts to be packaged are arranged and are then covered by a secondfilm adhered to the first film by means of applying heat and pressure,for example, is well known. Packaging of this type is known also as skinpackaging because it uses two films that are attached to one anotheraround the contour of the product, one of which takes the form of theproduct, and is disclosed, for example, in patent documentWO2015011076A1 belonging to the same applicant.

The skin packaging of products is well known in the food industry forpackaging meats, fish, cheese, ready-made meals and the like. Duringskin packaging, the product to be packaged is usually placed on a firstfilm or on trays previously formed in said first film by way of supportsin the packaging machine itself. Then said supports, with the productson them, are arranged in a sealing station, where they are covered witha second film. The second film is generally pre-heated in the packagingmachine before being introduced in the sealing station to increase itsdeformation capacity, and once it is arranged in the sealing station itis brought towards the walls of the sealing station by vacuum forgreater heating and softening. Then the vacuum on the film is releasedto cause the film to cover the entire product and adhere to the surfaceof the support not covered by the product, thereby forming a skin aroundthe product and on the support.

In machines of this type, conveyor means generally guides the bottomfilm along its entire path in the machine, and to that end the conveyormeans holds said bottom film and cause it to move. A common way ofholding said film is by means of clamps which laterally hold and movethe bottom film in the forward direction, such that when said conveyormeans moves forward (operated by a chain, for example), the clamps dragthe bottom film, causing it to move forward.

Additionally, proximate to the holding surface of the clamps,perforations are made in the bottom film that are used to apply thevacuum between the top film and the bottom film through same, such thatthe holding surface of the clamps is outside the sealing station and theperforations are arranged inside the sealing station, in the space wherethe products to be packaged are located. When the top film is arrangedon the bottom film in the sealing station, pins are introduced throughsaid perforations to assure they are open and to generate a vacuumbetween both films, while at the same time said pins tense the top filmwhile it is brought towards the walls of the sealing station, saidtensing being for preventing subsequent creasing. When the top film hasreached the suitable temperature in contact with the walls of thesealing station, it is aerated or positive pressure is applied on saidtop film, such that the vacuum generated between both films makes iteasier to seal the two films along the perimeter of the product andcause the top film to adapt to the contour of the product during thesealing operation. The perforated zone of the bottom film is thenseparated from the rest of the bottom film and disposed of. The sameoccurs with the part of the top film that is arranged on said zone. Thisentails a considerable amount of material to be disposed of (the zoneheld by the clamps and the zone in which the holes have been made).

Patent document WO2014180823A1 discloses a packaging machine whichintends to minimize the material to be disposed of. To that end,additional elements like those discussed above, for example, forsupporting the bottom film (or the top film) are not used in the sealingstation, such that it is not necessary to use excess film on which theseadditional elements would act. Before the sealing station, the bottomfilm is supported by conveyor means at its ends (coinciding with theflaps of the final package or final tray), and after the sealing stationthe conveyor means holds said ends of the bottom film (now furthermorehaving the top film adhered thereto) again. Although with this solutionit is not necessary to use additional material for supporting the filmsin the sealing station, the fact that the films are not held in thesealing station entails the need to use greater top film thicknesses toachieve suitable sealing, makes it necessary to perforate the inside ofthe package (the bottom film) to optimize sealing between both films andprevent creases and/or bubbles, and as the final package has beenpreviously secured by its own flaps means, said holding can mark ordamage said final package, which is not allowable and renders saidsolution to be unsuitable in many cases.

SUMMARY OF THE DISCLOSURE

According to one embodiment a skin packaging machine is provided thatcomprises a first feeding station for supplying a first continuous filmin a forward direction of the machine, a second feeding station forsupplying a second continuous film in the forward direction and abovethe first film, and a sealing station which is configured for receivingboth films and comprising an upper tool pressing on said films forsealing both films to one another. The upper tool comprises:

-   -   a closed holding contour pressing on the films and delimiting        the area of said films being sealed to one another,    -   a heating surface delimited by the holding contour and facing        said area corresponding to the second film,    -   heating means for heating the heating surface, and    -   suction means for bringing the second film towards said heating        surface for heating it.

The sealing station further comprises a sealing gasket attached to theholding contour for preventing direct contact of the upper tool with thefilms when said upper tool presses on them. The sealing gasketcomprises, on each side with respect to the forward direction, anoperation zone with a notched configuration which is facing the spacedelimited by said sealing gasket, such that when the second film isbrought towards the heating surface for heating, the second film tendsto tense up towards the heating surface in the notch-free areas of theoperation zone, becoming deformed, whereas the notches limit saiddeformation, thereby preventing with said limitation early contactbetween said second film, particularly in the zones of the notch-freearea of the sealing gasket, and said heating surface which could damagesaid second film while at the same time certain deformation is allowed.Particularly, deformation of the second film in a notch-free area of thesealing gasket is limited by the notches of said sealing gasket adjacentto said notch-free area. The notch-free areas comprising trencheslocated between the notches in the operation zone.

Therefore, when the second film is brought towards the heating surfacefor being heated, said second film tends to tense up as a result of thenotched configuration of the sealing gasket (particularly in thenotch-free areas), becoming deformed, without the need to incorporateadditional elements to perform said tensing up, whereas the actualconfiguration of the sealing gasket also limits said deformation (as aresult of the notches) for preventing early contact between said secondfilm and the heating surface of the upper tool. Without this notchedconfiguration of the sealing gasket, the entire second film would tendto become deformed towards the heating surface, without limitations andwithout achieving suitable tension for preventing creases in the finalpackage, for which reason it would be necessary to include additionalelements such as pins, for example, which are inserted through the firstfilm for tensing up the second film, and said additional elements wouldhave to be arranged within the space delimited by the holding contour,which would require increasing said space, and therefore the area of thefilms delimited by said holding contour, for generating packages of thesame size.

Therefore, with the proposed solution the need to incorporate saidadditional elements is eliminated, or should they be needed due to thefeatures of the second film, allows incorporating said elements beneaththe notch-free areas of the sealing gasket, the area of the filmsnecessary for one and the same package size being reduced, the amount ofmaterial to be used for one and the same package size therefore beingreduced, with the savings that this entails and the subsequent drop inpackaging process costs.

Since the process of deforming the second film requires certain time inorder to adapt to the contour of the sealing station and to heat thearea of the second film facing the heating surface, the second filmwould in this case experience excess heat, at least at the point whereit first came into contact with the heating surface, causing greaterdeformation of said point, which could damage the film, which is a riskthat has been avoided with the proposed solution. Therefore, thisdrawback is solved without additionally requiring the material of thesecond film to go beyond the holding contour over the sides, therequired material of the second film being reduced and the amount ofsaid second film to be disposed of accordingly being reduced.

This solution is particularly furthermore advantageous the thinner thesecond film is, because the less thick it is the more ductile it will beas it heats up and is therefore brought towards the heating surface morequickly, which would increase the risk of early contact with the heatingsurface. Therefore, this solution allows using less thick films actinglike a second film, which also reduces the amount of material used andthe packaging process cost.

These and other advantages and features will become evident in view ofthe drawings and of the detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a schematic view of a skin packaging machine according toone embodiment.

FIG. 2a is a partial section view of an upper tool and a lower tool ofthe sealing station of the machine of FIG. 1, tightly holding the filmsbetween them during sealing, in which the second film in the zone of anotch-free area of the sealing gasket is depicted by means of acontinuous line, and the same second film in the zone of a notch of saidsealing gasket is depicted by means of a discontinuous line.

FIG. 2b is a partial, perspective, section view of an upper tool and alower tool of the sealing station of the machine of FIG. 1, tightlyholding the films between them during sealing (the second film is notdepicted).

FIG. 2c is a side section view of the tools of the sealing station ofthe machine of FIG. 1, tightly holding the films between them duringsealing (the second film is not depicted).

FIG. 3 shows a sealing gasket of the sealing station of the machine ofFIG. 1.

FIG. 4a shows a perspective view of a package generated in the machineof FIG. 1, in the form of a tray, with a packaged product.

FIG. 4b shows a side view of the tray of FIG. 4a , with the packagedproduct.

DETAILED DESCRIPTION

FIG. 1 shows a schematic view of a skin packaging machine 100 accordingto one embodiment. The machine 100 is suitable for packaging products Parranged between a first continuous film 10 and a second continuous film20 sealed to one another around the perimeter of the product P arrangedbetween both by means of heat, and these are then cut for generatingindividual packages with a product P packaged therein. In some of thedrawings the products P are not depicted for the sake of clarity.

Continuous must be interpreted as the films 10 and 20 being suppliedwithout pre-cuts, i.e., without having been previously cut to the sizesrequired for the final package. Therefore, the films 10 and 20 can bestored in the form of reels, for example, and can be gradually unwoundfrom the corresponding reel to be supplied.

The machine 100 comprises a first feeding station 1 for supplying thefirst continuous film 10 in a forward direction A of the machine 100, asecond feeding station 2 for supplying the second continuous film 20 inthe forward direction A and above the first film 10, and a sealingstation 3 which is configured for receiving both films 10 and 20 in saidforward direction A, with the second film 20 above the first film 10,and for sealing them together using heat. Previously, particularlybefore the first film 10 is fed into the sealing station 3, the productsP to be packaged are arranged on said first film 10 in a specificmanner.

The skin packaging machines 100 works intermittently, one sealingoperation being performed in the sealing station 3 every machine cycle.Once a cycle is performed and the films 10 and 20 are stationary, saidfilms 10 and 20 are made to move in the forward direction A a specificdistance to perform a new machine cycle. In every machine cycle, oneproduct P is packaged in its corresponding package in the sealingstation 3, or a plurality of products P can be packaged simultaneously(each one in a corresponding package). For this last case, the productsP are arranged on the first film 10 before entering the sealing station3, forming a line in the forward direction A (or a plurality of parallellines), a plurality of products P being located in the sealing station 3in one and the same machine cycle.

The sealing station 3 comprises an upper tool 3.1 depicted in FIGS. 2a,2b and 2c , pressing on the films 10 and 20 and being supported on alower tool 3.2 to apply said pressure, both films 10 and 20 beingtightly held between both tools 3.1 and 3.2 during sealing. The uppertool 3.1 comprises at least:

-   -   one closed holding contour 3.10 pressing on the films 10 and 20        during sealing, and delimiting the area of said films 10 and 20        to be sealed together in every cycle of the machine 100,    -   one heating surface 3.4 delimited by the holding contour 3.10        and facing said area corresponding to the second film 20,    -   heating means (not depicted in the drawings) for heating the        heating surface 3.4, and    -   suction means for bringing the second film 20 towards said        heating surface 3.4 for heating, said heating surface 3.4        comprising a plurality of holes 3.41 that are part of the        suction means and through which said second film 20 is brought        towards said surface 3.4.

The suction means further comprise an actuator not depicted in thedrawings, causing said suction through said holes 3.41. Suction meansfor this purpose in skin packaging machines 100 are already known, soneither their operation nor their configuration will be described indetail. Likewise, heating means are also known and can be, for example,resistances configured for heating said heating surface 3.4 whenrequired.

The sealing station 3 further comprises a sealing gasket 3.12 which isattached to the holding contour 3.10 for preventing direct contact ofthe upper tool 3.1 and the films 10 and 20 during sealing, said films 10and 20 therefore being protected from heat in the holding contour 3.10,and this is shown by way of example in FIG. 3. On the sides with respectto the forward direction A, the sealing gasket 3.12 comprises anoperation zone 3.5 with a notched configuration which is facing thespace delimited by said sealing gasket 3.12, such that when the secondfilm 20 is brought towards the heating surface 3.4 for being heated, thesecond film 20 tends to tense up through the notch-free areas 3.51 ofthe operation zone 3.5 towards the heating surface 3.4, becomingdeformed, whereas the notches 3.52 limit said deformation, therebypreventing early contact between said second film 20 and said heatingsurface 3.4, particularly in the zones of the notch-free area 3.51. Thesecond film 20 tenses up and becomes deformed through said notch-freeareas 3.51, and the notches 3.52 prevent early contact between saiddeformed part of the second film 20 and the heating surface 3.4 in thezone of the sealing station 3 that is arranged on the notch-free areas3.51, thereby preventing the second film 20 from heating up too much insaid zones prone to early contact, and due to its ductility caused by ahigher temperature, causing damage to in the second film 20. Accordingto some embodiments there are provided two operation zones 3.5.According to some implementations the operation zones 3.5 are the sameand symmetrical with respect to the forward direction A.

The operation zone 3.5 therefore comprises a succession of notch-freeareas 3.51 and of notches 3.52 distributed in the forward direction A.According to some embodiments the distribution of the notch-free areas3.51 in the corresponding operation zone 3.5 and in the forwarddirection A is homogenous, the distribution of the notches 3.52 in saidoperation zone 3.5 and in the forward direction A therefore also beinghomogenous. According to some embodiments the length of all thenotch-free areas 3.51 is the same in the forward direction A, and thelength of the notches 3.52 is also the same in the forward direction A,although the length of one notch-free area 3.51 does not have to be thesame length as one notch 3.52. The value of lengths can depend ondifferent factors, such as the material, the properties or the thicknessof the second film 20, for example.

The length of the notch-free areas 3.51 and the length of the notches3.52 in the forward direction A are related to the deformation to beapplied on the second film 20 and to the limitation of said deformation,respectively. The length of the notch-free areas 3.51 is long enough tocause said deformation and short enough to prevent early contact betweensaid second film 20 and the heating surface 3.4. In turn, the length ofthe notches 3.52 is long enough to prevent early contact between saidsecond film 20 and the heating surface 3.4 and short enough to allowdeformation of the second film 20.

The width of the notch-free areas 3.51 and the width of the notches 3.52in a direction transverse to the forward direction A are related to thedeformation to be applied on the second film 20 and to the limitation ofsaid deformation, respectively. The width of the notch-free areas 3.51is big enough to cause said deformation and small enough to preventearly contact between said second film 20 and the heating surface 3.4.In turn, the width of the notches 3.52 is big enough to prevent earlycontact between said second film 20 and the heating surface 3.4 andsmall enough to allow deformation of the second film 20.

The thickness (height) of the sealing gasket 3.12 in the zonescorresponding with the notch-free areas 3.51 and the thickness of saidsealing gasket 3.12 in the zones corresponding with the notches 3.52 arerelated to the deformation to be applied on the second film 20 and tothe limitation of said deformation, respectively. The thickness in thezones corresponding with the notch-free areas 3.51 is big enough tocause said deformation and small enough to prevent early contact betweensaid second film 20 and the heating surface 3.4. In turn, the thicknessof said sealing gasket 3.12 in the zones corresponding with the notches3.52 is big enough to prevent early contact between said second film 20and the heating surface 3.4 and small enough to allow the deformation ofthe second film 20. Preferably, the thickness of the sealing gasket 3.12is homogenous (the same) around its entire perimeter.

Preferably, the length, width and thickness of the sealing gasket 3.12in the zone corresponding with the notch-free areas 3.51 and the length,width and thickness of the sealing gasket in the zone corresponding withthe notches 3.52 are related to the deformation to be applied on thesecond film 20 and to the limitation of said deformation, respectively,and said lengths, widths and thicknesses are related to one another toallow said deformation and to prevent said early contact between thesecond film 20 and the heating surface 3.4.

In some cases, the second film 20 can be exposed to a heating processbefore entering the sealing station 3, in which case the machine 100comprises a pre-heating station (not depicted in the drawings) withheating means, such as a heating plate for example, arranged upstreamfrom said sealing station 3 in the forward direction A. The need forheating the second film 20 in the sealing station 3 decreases as itstarts from a higher temperature in said sealing station 3 compared tothe case in which it is lacking said prior heating plate.

The films 10 and 20 are supplied in the forward direction Aintermittently, such that in every machine cycle a first specific areaof the second film 20 is exposed to the heat of the heating plate and asecond area of said second film 20 is sealed to the first film 10 in thesealing station 3. In the following cycle, said first area is arrangedin the sealing station, becoming a second area sealed to the first film10. Due to the configuration of the heating plate and the supplydirection of the second film 20 to the zone where it is heated by saidheating plate, the end that is farthest downstream in the forwarddirection A of the second film 20 is no longer heated before enteringthe sealing station 3, such that it is shrink-wrapped and introduced inthe sealing station 3 with a lower temperature than the rest of thesecond film 20. In the following cycle, in which said end will be theend that is farthest downstream in the forward direction A of the secondfilm 20 being sealed to the first film 10 in the sealing station 3, saidend is less hot and has a lower risk of adhering to the heating surface3.4, and it also has a lower risk of creased being generated therein dueto the shrink-wrapping process to which it was previously subjected. Thehigher the temperature of the second film 20, the more ductile it is,such that since said end is at a lower temperature, the rest of thesecond film 20 is more ductile and more easily and more quickly broughttowards the heating surface 3.4, for which reason there is no risk ofsaid end adhering to said heating surface 3.4 too soon.

For this reason, for these cases each operation zone 3.5 of the sealinggasket 3.12 can comprise a length that is smaller than the total lengthof said sealing gasket 3.12, each operation zone 3.5 extending in theforward direction A from the entrance into the sealing station 3 to aspecific intermediate point. The operation zone 3.5 of the sealinggasket 3.12 therefore corresponds with the zone of the sealing station 3where the second film 20 is provided with a higher initial temperature.As a result, the zone of the sealing gasket 3.12 associated with theless hot end of the area of the second film 20 to be sealed to the firstfilm 10 in the sealing station 3 is not notched, but nevertheless sinceit is less hot, it does not present the risk of adhering to the heatingsurface 3.4 when not wanted, and since it was previously subjected to ashrink-wrapping process, the risk of generating creases in the packageis eliminated.

In the embodiment of the machine 100 shown in the drawings, the firstfeeding station 1 comprises a cutting station 13 upstream from thesealing station 3 in the forward direction A, with at least one cuttingtool which is suitable for generating at least one opening (not depictedin the drawings) in the first film 10, to later in the sealing station 3generate a vacuum in the space existing between the area of the twofilms 10 and 20 delimited by the holding contour 3.10. If a plurality ofproducts P is going to be simultaneously packaged in the sealing station3, each one in its own package, this opening serves to generate asimultaneous vacuum in all the packages. Naturally, if instead of oneopening more openings are made (both if only one product P is packagedand if a plurality of products P is simultaneously packaged), the vacuumis generated more quickly, and in some cases more efficiently. Thesealing station 3 therefore receives the first film 10 with said openingand comprises vacuum means (not depicted in the drawings) for applying avacuum between the two films 10 and 20 through said opening (in thementioned space), during the sealing of said films 10 and 20, such thatthe product P arranged in said space is vacuum packaged.

The cutting tool is configured such that, or arranged such that in themachine 100 such that, the opening made on the first film 10 coincideswith a notch-free area 3.51 of the operation zone 3.5 of the sealinggasket 3.12 of the sealing station 3 during the sealing of the two films10 and 20. The aforementioned vacuum is thereby generated without havingto make the opening at a point that will pertain to the final packageand would therefore have to comply with a series of requirements (closedlater) and would affect the appearance of the package. Furthermore,unlike what occurs in the prior art where to generate said vacuumwithout the necessary opening affecting the final package, said openingis made on the sides of the films 10 and 20 outside the holding contour3.10; here, said films 10 and 20 do not required being acted on beyondsaid holding contour 3.10, and it is therefore not necessary to increasethe width of said films 10 and 20 beyond said holding contour 3.10 forthis purpose. This allows reducing the generated remnant 60 of the films10 and 20, remnant 60 being understood as the material from said films10 and 20 that is subsequently eliminated or disposed of, with thesubsequent material and cost savings. Preferably, the remnant 60 iscollected in a collecting station 6.

According to some embodiments the cutting tool is configured for makingan opening for each of the notch-free areas 3.51 of the operation zone3.5 of the sealing gasket 3.12 of the sealing station 3, although it issometimes not necessary to make one opening for each of the notch-freeareas 3.51.

In the embodiment of the machine 100 shown in the drawings, the finalpackages in which the products P are packaged can be trays 4 covered bya cover film. The trays 4 are generated from the first film 10, and thecover film is generated from the second film 20. Each tray 4 comprises abase 40 on which the product P is arranged, a flap 41 surrounding thebase 40 at a different height and a wall 42 joining the flap 41 with thebase 40, as depicted by way of example in FIGS. 4a and 4b , which show afinal package (in the form of a tray) with a packaged product P.Therefore, in said embodiment the first feeding station 1 comprises afeeder 11 supplying the first continuous film 10 from a reel of film forexample, and a forming station 12 downstream from the feeder 11 in theforward direction A. The forming station 12 is configured for generatinga plurality of cavities 15 in the first film 10 in the forward directionA, as the first film 10 moves forward in said forward direction A, inone or more parallel lines, each cavity 15 being associated with a tray4. The sealing station 3 is downstream from the forming station 12 inthe forward direction A, such that said sealing station 3 receives saidfirst film 10 already formed (with the cavities 15). The cutting tool ispreferably upstream from the forming station 12 in the forward directionA, but it could also be downstream from the forming station 12, betweensaid forming station 12 and the sealing station 3, in said forwarddirection A.

In the embodiment shown in the drawings, the machine 100 furthercomprises a separating station 5 arranged downstream from the sealingstation 3 in the forward direction A, and configured for cutting thefilms 10 and 20 already sealed to one another and with the product Ptherein, thereby generating individual packages (each with itscorresponding product P). The transverse and/or longitudinal cutsrequired for obtaining individual packages, depending on how theproducts P are packaged (in a single line in the forward direction A orin a plurality of parallel lines) are made in the separating station 5.

Each final package therefore comprises a tray 4 like the one discussedabove (in the particular case that the final packages are of the traytype), with a cavity 15 and a flap 41 around said cavity 15. The formingstation 12 is configured for forming a cavity 15 such that a width ofthe first film 10 extending from the lateral end of the first film 10 tothe lateral end of said cavities 15 is left unformed, and the sealingstation 3 is configured so that the sealing gasket 3.12 is supported onsaid non-formed zone for sealing the two films 10 and 20 to one another.Particularly, the sealing gasket 3.12 is supported on a part of saidnon-formed zone that is located more outwardly than the part that willlater be the flap 41 of the corresponding tray 4. Acting on a zone ofthe films 10 and 20 that will later become part of an individualpackage, i.e., the flap 41, is avoided, which prevents marking said flap41. In some cases, the zone that will become the flap 41 of a final tray4 is also formed, so in these cases the sealing gasket 3.12 is supportedon the non-formed zone. Therefore, in the embodiment shown in thedrawings the configuration of the holding contour 3.10 and theconfiguration of the forming station 12 are related and comply withrelated parameters for the correct packaging of products P in saidmachine 100. Furthermore, the opening (or openings) made by the cuttingtool is also located outside the flap of each tray 4, such that thevacuum of the package can be generated without the appearance of thetray 4 being affected as a result.

Additionally, the sealing station 3 can comprise additional elements notdepicted in the drawings in the form of pins, for example, to assure theopening of the openings of the first film 10 while generating the vacuumbetween the first film 10 and the second film 20, and/or to tense up thesecond film 20 as it is brought towards the heating surface 3.4. Saidadditional elements are arranged in the lower tool 3.2 of the sealingstation 3 below the notch-free areas 3.51 of the sealing gasket 3.12 ofthe upper tool 3.1, such that they are introduced through the openingsof the first film 10 in the space of the notch-free areas 3.51 of thesealing gasket 3.12 and perform their function without generating alarger amount of remnant 60 of films 10 and 20.

What is claimed is:
 1. A sealing station configured to receive a firstfilm and a second film disposed above the first film, the sealingstation having a rearward entrance side and a forward exit side andconfigured to seal the second film to the first film, the sealingstation comprising: a lower tool that is configured to support the firstfilm; and an upper tool positioned above the lower tool, in a firstarrangement the upper and lower tools are in contact with one another,in a second arrangement the upper and lower tools are not in contactwith one another, the upper tool including a heating surface and agasket that is configured to urge the second film against the first filmwhen the upper and lower tools are in the second arrangement, the gaskethaving a first side with a first operation zone, the first operationzone including notches that are separated by trenches, the notchesfacing inward into a space delimited by the gasket, the heating surfacehaving a plurality of suction holes that are configured to draw thesecond film towards the heating surface when a suction is appliedthrough the suction holes, the notches and trenches of the firstoperation zone being configured to cause the second film to be deformedinside the trenches in a tensed state to inhibit or reduce the formationof creases in the second film when the second film is drawn toward theheating surface.
 2. The sealing station according to claim 1, whereinthe notches of the first operation zone are configured to limit thedeformation of the second film in the trenches in a manner thatpostpones a contact of the second film with the heating surface when thesecond film is drawn towards the heating surface.
 3. The sealing stationaccording to claim 1, wherein the gasket comprises a second sideopposite the first side, the first and second sides of the gasketextending lengthwise in a direction transverse to the rearward entranceside and forward exit side of the sealing station, the second side thegasket having a second operation zone, the second operation zoneincluding notches that are separated by trenches, the notches facinginward into the space delimited by the gasket, the notches and trenchesof the second operation zone being configured to cause the second filmto be deformed inside the trenches in a tensed state to inhibit theformation of creases in the second film when the second film is drawntoward the heating surface.
 4. The sealing station according to claim 3,wherein the notches of the second operation zone are configured to limitthe deformation of the second film in the trenches in a manner thatpostpones a contact of the second film with the heating surface when thesecond film is drawn towards the heating surface.
 5. The sealing stationaccording to claim 1, wherein the trenches of the first operation zonehave a same first width and the notches of the first operation zone havea same second width, the second width being greater than the firstwidth.
 6. The sealing station according to claim 3, wherein the trenchesof the first and second operation zones have a same first width and thenotches of the first and second operation zones have a same secondwidth, the second width being greater than the first width.
 7. Thesealing station according to claim 1, wherein the gasket has a firstwidth outside the first operation zone, the notches of the firstoperation zone have a second width that is substantially the same as thefirst width.
 8. The sealing station according to claim 3, wherein thegasket has a first width outside the first and second operation zones,the notches of the first and second operation zones have a second widththat is substantially the same as the first width.
 9. The sealingstation according to claim 1, wherein the gasket has a thickness that issubstantially uniform around an entire perimeter of the gasket.
 10. Thesealing station according to claim 1, wherein the trenches of the firstoperation zone have a same length and the notches of the first operationzone have a same second length.
 11. The sealing station according toclaim 3, wherein the trenches of the first and second operation zoneshave a same length and the notches of the first and second operationzones have a same second length.
 11. The sealing station according toclaim 1, wherein the first side of the gasket is disposed transverse toat least one of the rearward entrance side and forward exit side of thesealing station, the first side having a first length, the firstoperation zone extending less than the entire first length.
 12. Thesealing station according to claim 3, wherein the first and second sidesof the gasket are each disposed transverse to at least one of therearward entrance side and forward exit side of the sealing station, thefirst side having a first length, the first operation zone extendingless than the entire first length, the second side having a secondlength, the first operation zone extending less than the entire secondlength.
 13. The sealing station according to claim 1, wherein firstoperation zone is located nearer the rearward entrance side of thesealing station than to the forward exit side of the sealing station.14. The sealing station according to claim 3, wherein the first andsecond sides of the gasket are arranged substantially parallel to oneanother with each of the first and second operation zones being locatednearer the rearward entrance side of the sealing station than to theforward exit side of the sealing station.
 15. A packaging machinecomprising: a first feeding station for supplying a first film in aforward direction of the packaging machine; a second feeding station forsupplying a second film in the forward direction and above the firstfilm; and a sealing station that includes a lower tool and an uppertool, the lower tool being configured to support the first film, in afirst arrangement the upper and lower tools are in contact with oneanother, in a second arrangement the upper and lower tools are not incontact with one another, the upper tool including a heating surface anda gasket that is configured to urge the second film against the firstfilm when the upper and lower tools are in the second arrangement, thegasket having a side with an operation zone, the operation zoneincluding notches that are separated by trenches, the notches facinginward into a space delimited by the gasket, the heating surface havinga plurality of suction holes that are configured to draw the second filmtowards the heating surface when a suction is applied through thesuction holes, the notches and trenches of the first operation zonebeing configured to cause the second film to be deformed inside thetrenches in a tensed state to inhibit or reduce the formation of creasesin the second film when the second film is drawn toward and heated bythe heating surface.
 16. The packaging machine according to claim 15,further comprising a pre-heating station located upstream from thesealing station in the forward direction for pre-heating the second filmbefore being supplied to the sealing station, the sealing station havinga rearward entrance side and a forward exit side, the operation zonebeing located nearer the rearward entrance side of the sealing stationthan to the forward exit side of the sealing station.
 17. The packagingmachine according to claim 15, wherein the first feeding stationincludes a cutting station upstream from the sealing station in theforward direction, the cutting station having a cutting tool that issuitable for generating at least one opening in the first film, thesealing station comprising vacuum means for applying a vacuum betweenthe first and second films through the at least one opening during thesealing of the first and second films, the cutting tool being configuredso that, or arranged in the packaging machine such that the at least oneopening made in the first film coincides with a trench of the operationzone of the gasket during the sealing of the first and second films. 18.The packaging machine according to claim 17, wherein the cutting tool isconfigured for making an opening for each of the trenches of theoperation zone of the gasket.
 19. The packaging machine according toclaim 17, wherein the sealing station comprises at least one additionalelement arranged in the lower tool that is configured for beingintroduced through the at least one opening made by the cutting tool inthe first film.
 20. The packaging machine according to any of claim 15,wherein the first feeding station comprises a feeder supplying the firstfilm and a forming station downstream from the feeder in the forwarddirection, the forming station being configured for sequentiallygenerate a plurality of cavities in the first film in the forwarddirection, the packaging machine comprising a separating stationarranged downstream the sealing station in the forward direction andconfigured for cutting the first and second films to generate individualpackages comprising a tray with a corresponding cavity and a flap aroundthe cavity, the forming station being configured to form the cavity suchthat a width on the sides of the first film extending from a lateral endof the cavity to an end of the first film is left unformed, the sealingstation being configured so that the gasket is supported on the firstand second films beyond the flap, towards an outer side of the first andsecond films during the sealing of the first and second films.